High clearance scaffold



Dec. 15, 1959 Filed Jan. 7, 1957 C. F. GROVER ET AL HIGH CLEARANCE SCAFFOLD 4 Sheets-Sheet l INVENTORS. Ch ar/es E Graver Paul E Slayer THE IR A TTORNE Y5 Dec. 15, 1959 c. F. GROVER ET AL HIGH CLEARANCE SCAFFOLD 4 Shets-Sheet 2 Filed Jan. 7, 195'? i. A 46c Fig. /4 Fig. /5

Charles E Graver Paul E. Slayer j/cW a IN V EN TORS.

THE IR A TTORNE Y5 Dec. 15, 1959 c.- F. GROVER ETAL 2,917,129

- HIGH CLEARANCE SCAFFOLD Filed Jan. 7, 1957 4 Sheets-Sheet 3 INVENTORS. Charles E Grover Paul E. Stayer THE IR A T'TORNE Y5 C. F. GROVER ET AL HIGH CLEARANCE SCAFFOLD Dec. 15, 1959 4 Sheets-Sheet 4 Filed Jan. 7, 1957 mmvroks. Charles E Grover Paul E. Slayer 710 M4 BY 5m THE IR A TTORNE Y5 United States Patent HIGH CLEARANCE SCAFFOLD Charles F. Grover and Paul E. Stoyer, Greenville, Pa., assignors to R. D. Werner Co. Inc., Greeuville, Pa., a corporation of Pennsylvania Application January 7, 1957, Serial No. 632,916

8 Claims. (Cl. 182-152) This invention relates to a collapsible scaffold construction, unit or tower and particularly, to a high clearance type.

A phase of the invention deals with the provision of a collapsible scaffold that may be easily moved or rolled in its expanded or assembled relationship and that may be easily carried or transported in its collapsed or disassembled relationship.

There has been an urgent need for relatively inexpensive, safe and practical scaffold equipment, such as may be used for repairing, cleaning, painting, renovating, and adding installations or equipment to building constructions. Scaffold equipment is particularly important from the standpoint of public buildings, such as churches, halls, office buildings, factories, etc., although it doeshave practical utilization from the standpoint of homes in its lesser height assemblies. The so-called rolling tower or tier build-up type of scaffold is gaining acceptance in this connection, in that it does not require hitches that mar or damage the building construction, may be collapsed into a smaller area, and may be safely utilized.

We have determined that in many utilizations it is desirable to, if possible, so employ the scaffold as to avoid the necessity for shifting or moving floor obstacles such as desks, book cases, machinery, etc., that may be installed within the interior of a building. In such an event, drop cloths may be used to protect the equipment and the tedius and expensive moving operations may be eliminated. As a result, repair or maintenance may be efiected more quickly and the particular room space involved may be more easily placed in a productive or useful status.

' We have discovered that there is a definite problem involved in producing a relatively simple and compact, space-conserving and collapsible type of scaffold construction which will satisfy the requirements for an obstaclebridging or spanning type and particularly, where a single unit or assembly is, itself, to provide the spanning action.

It has thus been an object of our invention to provide a solution to this problem in the form of a relatively simple and practical scaffold unit or construction;

Another object has been to devise a new and improved type of scaffold unit or construction and particularly, one of a type that is collapsible and easily transported;

It has been a further object of our inventionto provide an improved collapsible scaffold construction that will better meet strength and safety requirements, that will boot a span type, will not have an excessive weight, and that may be fixed or locked in its expanded relationship until the user desires to collapse it.

Astill further object of our invention has been to provide a high clearance type of scaffold unit which may be moved from place to place, will be collapsible, and maybe employed sectionally or in tiers as a verticalcolumn of the desired height for the particular type of building maintenance or repair problem involved;

These and other objects willappear to thgse skilled in of Figure 1, illustrating it on a slightly enlarged scale and also in an upright relationship;

Figure 3 is an end view taken along the line IIIIII of and on the same scale as Figure 2 and showing the con-' struction in the same upright position as Figures 1 and 2; Figure 3A is a top plan view of the construction of and on the same scale as Figures 2 and 3; it also shows the unit in its upright position;

Figure 4 is a side view in elevation of the structure of Figures 1 to 3A showing it in a fully collapsed, disassembled or folded relationship; this figure has a greatly' enlarged scale with respect to Figures 1 to 3A;

Figure 5 is a greatly enlarged fragmental view taken in the same direction as Figure 3 and showing a latching means for the construction of Figures 1 to 4;

Figure 6 is a sectional fragment on the same scale as and taken in the same direction as Figure 5; in this figure the latching means is in a latching position while it is in a withdrawn or unlatched position in Figure 5;

Figures 7, 8 and 9 are enlarged fragmental detail views of an intermediate, overhead-platform, floor-swing means or hinge construction that is shown employed in the construction of our invention;

'Figure 7 is a side fragment showing the swing means in its fully open or upwardly swung-out position, such as accomplished when the unit is in its folded relationship illustrated in Figure 4;

Figure 8 is a view similar to Figure 7 showing the structure in its fully swung-down and opposed relationship such as to support aplatform or floor section in a substantially horizontal position;

Figure 11 is an end fragment in elevation taken along the line IX--lX of Figure 8 and showing the swing means in the same position as Figure 8;

Figures 10 to 13 are diagrammatic views showing how a scaffold construction or unit of our invention may be progressively moved, pivoted or shifted from a fully expanded upright position, such as shown in Figures 1 and 2, to a final fully collapsed position for carrying and storing purposes, such as illustrated in Figure 4;

Figure 11 illustrates how an operator may stand at one (the right) end of the unit and initiate a collapsing of its frame by first upwardly-releasing an outer end of a half of its floor part or section with respect to an adjacent end support or upright section, and then by swinging or pivoting the same adjacent end support section (counterclockwise) downwardly or inwardly from its upper end and (counterclockwise) upwardly or outwardly from its lower end;

In Figure 12, the adjacent support or upright section has been swung to complete its movement into a substantially parallel and abutting relation with an adjacent bridge member pair, and the floor section half has been swung into an abutting and substantially parallel relation, directly with the adjacent support section and indirectly, With the adjacent bridge member pair;

To complete the folding operation, as illustrated in Figure 13, the same type of operation of Figures 10 and 12 is accomplished, but with the operator standing at a left end of the unit;

Figure 13 illustrates a preliminary positioning of the left hand upright section, the other floor section half, and an adjacent bridge member pair; the sections and halves are all pivoted or swung on, about or by the swing means as the unit is collapsed and the swing means is moved to its spread position of Figures 4 and 7; at this time, all the sections and halves attain the substantially parallel relationship of Figure 4;

Fi ure 14 i an e r e ve ica f m f c erstructure illustrating how units of our invention are aligned before being assembled in vertiealt columns or tiers;

' Figure 15 is a vertical section of the structure of Figure 14 showing it in a fully assembled relation; and

Figure 16 is a horizontal section taken along the line of Figure 15. Y

We have solved the problem of a practical, efficient, simple, easily assembled and disassembled, carried, and stored scaffold unit or structure. This has been accomplished by devising a self-supporting unit having supporting end sections or parts that are to be positioned in a spaced-apart relationship with each other and, at least one of which may provide or carry a ladder. A floor or platform section or frame is provided in two halves or foldable parts C and C that form a span of a cantilever and are carried in the form of swing frames having a substantially common intermediate swing and supporting means 30. The means 30 is downwardly-inwardly offset with respect to the floor section (C, C) and is carried on transverse swing shaft, arm or member 18a. The swing support is such that weight carried on the platform or floor tends to strengthen or retain a spread, horizontal positioning or cooperative alignment of the halves.

Although we make it possible to move or swing upright end sections A and B inwardly to fold the structure, there is no danger of. an accidental collapse under the. supported wdght of a worker, either from the standpoint of a failure of its parts or from the standpoint of a slip-out or swing of a portion of its parts, for example, ofone or both of its floor parts. The hinging is such that the floor section is only moved into a collapsed position in a direction counter to the direction of normal application of the weight of an operator. In other words, collapse cannot be effected by pressing downwardly on its swing hinge means 30, but only by pressing upwardly on it and on associated bridge or strut member pairs (2t)- 2-1 and 20'-:-21'), representing sections D and; D. Each fioor section half or part (C and C) at its outer end portion has a clamping, latching, locking or clamping means 26 that is moved downwardly into a detachably-engaging, clamping r latching relationship with respect to a top rail or upper.

transverse member 14d of an associated end section or part (A or B). Thus, to release an end section (A or B) to swing it about inner swing mounting or means 30, it is necessary to either move the end section downwardly or an associated partor half of the floor section upwardly. This is a further safety feature of the construction.

Referring particularly to Figures 1- to 3A of the drawings, our collapsible scaffold tower construction or unit has a pair of opposed and longitudinally spaced-apart upright. end frames or support sections or parts A and B. Each upright section A and B is of rectangular frame construction and similar portions, of one part, such as A,

have been given similar numerals to the other swing part B. Exactly the same numerals are used where the portions are identical and prime afiixes are used where they are. similar but slightly different. Each end support sectionorframe A and B is adapted, to carry a half orpart of platform or floor section C and C of cantilever-like suspension or mounting. A covering or platform means, such as plywood 11, may be secured, as by J-bolts, to rectangular -frarne-defining longitudinally and transversely extending members 23 and 24.

In sections A and B, an end; column or post 12 cooperates with a transversely-spaced similar. end column or post 13, to define upright members at each end section. Cross ties, transverse or rail end members 14, 14a, 14b, 14c and 14 1 are secured by connector T to the upright columnaleg members, or posts 12 and 13 to define a cqrnpieteend frame. orupright structure. As-shown parand in a vertical column of tiers. In this connection, one

end may be reserved for up travel and the other for down travel to thus provide a maximum efiiciency and safety of utilization.

Each end frame section may, as shown particularly in Figure 3, be reinforced by-corner, diagonal, cross-brace or tie pieces or members 16. The pieces 16 are preferably of flat or metal bar construction and are secured in place at their ends by brazing or welding. The column members 12 and 13, the bottom-most to the top-most of rail members 14 to 14d, and the tie or diagonal pieces 16 all provide a strong unitary and rigid end structure for each section A and B of the scaffold.

We provide a pivot or swing connection between the swing or hinge means 36 and end sections A and B that lies somewhat at a mid height of the end sections. It is a double swing connection of normal diagonal extension towards a mid or intermediate joint portion of the platform or floor section or structure. Opposed pairs 20-21 and Z0-'.I{Z 1' of swing arm, bridging or strut members are empioyed. An inner end of each floor section half (C Q) s i t thr h Swing m ns 5 a its qes fati s as ortio o hinged swing memb r or 31 diagonal strut, swing arm, or bridging members 20. and 2 1 (or 24) and 21), and a pair of swing collars or trunnions 19 on an inwardly-offset swing support, cross rail or transverse member 18.

The transverse swing support cross member 18 is secured at its ends to extend parallel to and in an inwardly.- ofr'set relation along its associated end section A or B by connectors 17 of modified T shape. As shown by Figures 1 and 2, the bridging member pairs 2821 and 2ii'2 1' extend in an angular relationship to and with respect to the post members 12 and 13. Also, the bridging member pairs are positioned centrally of the platform orfloor C --Q section and centrally or midway along the height of the end sections A and B.

Thus, when the structure is in its fully expanded relationship, it has a high-clearance, central swing suspension that strongly supports overhead weight, but may. be easily folded or collapsed and erected by one man,

We have shown tubular or pipe-shaped members for the structure that may be made of relatively light weight metal, such as thin-wall steel, magnesium, aluminum and aluminum alloys. may. also be of a non-conductive or insulating material, such as of plastic or of fiberglass-reinforced plastic, Mounting or securing of plastic-like members may be effected by employing cementing materials, heat, etc. Metal members may be brazed or welded within the sock ets. of connectors 15 and 17, of wings 31 and 31', etc.

Additional units may be added vertically, as needed (see Figures 14 to 16), by providing projecting stacking 13b) of each end post or leg member (12 and 13) of an,

upper one ofa pair of'scatt'old units. The stacking pin 46 projects downwardly therefrom and is secured in position by suitable means, such as a rosette weld d employing weld metal w. A downwardly-spaced annular rim or stop-limit-ring' portion 46b projects outwardly from the The tubular or pipe-shaped members portion 46a to provide an abutment for the extreme lower edge of the upper end post member. The lower part of the stacking pin 46 that is adapted to fit or telescope into the upper end of a lower unit of our construction, has an upper or cylindrical portion 46c and a lower tapered portion 46d. The tapered portion 46d facilitates the introduction into and removal of the fitting 46 from upper T connector and upper end 12a (or 13a) of the end post of a lower unit.

When, as shown in Figure 15, an upper unit is fully mounted upon or inserted in a lower unit of our assembly construction, the annular rim 46b acts as a stop flange to not only protect the upper edge of the upper end portion 12a (or 13a) of end post of the lower unit within which the fitting 46 projects, but to also limit the maximum insertion of the fitting. To provide full security of a fastened, locked or latched assembled relationship between a pair of a series of vertical tiers made up of scaffold units, we employ a removable clip spring means or clamp 47 for each upper end post to resiliently or flexibly clamp thereabout. The clip means 47 has (as shown particularly in Figures 15 and 16) a pair of open, spread wing portions, so that it may be spread against its tension and then raised, lowered or removed.

A locking or latching plug-in part or pin 48 is carried within a hole projecting through a mid-body portion of the clip 47. It will be noted that the mid-body portion is strengthened by a curvilinear, thickened portion or rib 47a. The upper end portion (12a or 13a) of each end post 12 (and 13) of a lower'unit of a'pair of stacked units has vertically spaced-apart holes c therealong to register with corresponding holes 46a in the stacking pin or connector 46. Thus, when a suitable assembled relationship has been obtained in stacking a pair of units, this relationship may be assured or retained by inserting the locking or latching plug 48 through aligned holes c and 46e (see Figure 15). When the spring clip 47 has been spread, the plug 48, of course, can be removed. The plug 48 has an inwardly-projecting cylindrical portion 48a, a mounting neck portion which projects through the hole in the spring clip 47, and an outer retainer (rivet) head 48c that projects from the neck 48b on the outside of the clip 47. Thus, the plug 48 is retained for ready utilization by the spring clip 47. In Figure 16, a small diameter, spring-pressed hold pin 48b is shown. When fitting 46 has been removed, plug 48 may be carried to project within a lower one of the holes c (its storage position).

Swing collar, sleeve portion or trunnion means 19 on the lower end of each strut member 20 and 21 (or 20 and 21') has a diameter substantially corresponding to the outer diameter of the swing rail or cross member 18 and may be held in longitudinal alignment by secured-on positioning or limit collars 32'of ring-like form, see particularly Figures 1 and 3. At its upper end, each member 20 and 21 has a swing collar, sleeve portion or trunnion 19a that pivotally mounts it on an upper, transverselyextending swing shaft or rail member 18a (see Figures 1 and 3). The swing support arm, member or shaft 18a is inwardly-offset underneath the floor section to both pivot the parts of the floor section together and to intermediate length or height portions of the end sections A and B. This is accomplished through the bridge or strut frame structures or sections D and D. Limit collars or rings 32 keep swing collars 19 and 19a in lateral alignment on the swing support members 18 and 18a. The rings 32 may be secured in position on the members by set screws or by weld metal, etc.

Ends of the upper swing member 18a have securelymounted hinge plugs or plug closures 33, see Figure 9 (if it is of hollow construction). The closures 33 may be of a screw or bolt-expanded type to provide an expansion fit. Endwise-extending threaded and headed pivot pin end portions or bolts 34 project from opposite ends of the swing member 18a and extend (as shown particularly in Figure 9) through aligned hole portions 31a and 31'a of the'swing means 30. Spacer washers 35 and bolt head 34a complete the mounting. It will be noted that each bolt or pivot screw 34 has a male thread portion that cooperates with a threaded bore 33a within each plug end 33 of the swing support member 18a.

As shown in Figures 1 to 3, the upper swing member 18a is supported by the two pairs of folding diagonal or oblique strut, bridging or swing members 20 and 21 and 20' and 21 and by the swing connection between the pair of transversely oppositely-positioned hinged swing wings 31 and 31. Each swing means 30 is of an underslung type and has the pair of complementary swing parts or wing parts 31 and 31'. Each wing part (see Figures 7 to 9) is secured at its outer end on said rail or longitudinally-extending fioor members 23 and, at right angles thereto, to transverse end members 24 to retain them (as shown particularly in Figure 3A) in a perpendicular or right angular relationship with each other.

Cruciform portions 31 are carried on each wing 31 and 31' to slidably receive thereon the end portions of the members 24 which are shown of tubular form. Brazing or welding may be employed to secure the members 24 on the portions 31 Members 23 are secured in position within sleeve portions 31e and 31e of the wings.

To limit the maximum inward and downward movement of each swing hinge means 30, each of its wing parts 31 and 31' is provided with a downwardly-extending and outwardly-projecting abutment shoulder 31b (or 31b).

- hole portions 310 and 31'c that are adapted to be in alignment when the wing parts have been moved to the fully closed or abutting position of Figure 10. A spring latch type of plug means 36 is shown (see Figures 5, 6, 8 and 9) which has a mounting sleeve or plug 37 secured by weld metal w to the wing 31 within a larger diameter hole portion 310. A manual pull-out or release cup or cap 39 has an outer knurled surface, projects from the outer end of sleeve 37, and is secured for movement with a latch head or tongue 40 by a cross or bayonet pin 38. It will be noted that the sleeve 37 has a forwardly-elongated slotted portion at 37a to by-pass the pin 38 and permit relative latching and unlatcning movement of latch tongue 4% with respect to the sleeve. By turning knurled-surface cap 39, the pin 38 may be moved into a locked position in a transverse slotted portion 37b (see Figure 6) to hold latchtongue 40 in a withdrawn position.

A compression spring 41 is operatively carried within the bore of the outer end portion of the sleeve 37 to fitover a reduced outer end portion 40b of the latch tongue 40. The spring 41 thus normally resiliently urges the tongue 40 to its latching or righthand position of Figure 6. The tongue 40 will snap into smaller diameter hole 31'c when the wings 31 and 31 are moved to the position of Figure 8. Head portion 49a of the tongue is beveled to facilitate its snap-in action; it is withdrawn from the hole 31's to unlatch the wing portions with respect to each other by pulling the release cap 39 outwardly.

Opposite or outer ends of the side members 23 (as shown particularly in Figures 1, 3 and 3A) have frame lock or clamp means 26 that is of a downwardly overlatching and an upwardly oif-unlatching type having latching portions provided with yieldable or releasable latching fingers. Cruciform end portions receive the end por tions of the members 23.

When the structure has been moved to the folded position of Figure 4, we may make use of a hold means or clamp 42 (see also Figures 2 and 3). As shown, the retaining or hold means 42 has a band which projects or 7 clamps around the member 18'. It also has an open spring finger 42a. The device may be swung to any desired position on, the member 18, for example, from a vertical to a horizontal position to cause the opposed member 18 of the other end section to be received by the open springfinger portion 42a.

Although a particular type of foot construction or caster mounting is not a part of our presentinvent-ion, we have shown (in Figures 1, 2 3 and 4) a structure which has a wheel or caster mount 43. The mount 43 may be secured within or mounted in a vertically adjustable relation with respect to hollow lower ends 12b and 13b of the post members 12 and 13. A journaled wheel or caster 44 has a pin support 44a that is carried by each mount 43 within an adjustment slot. A swing handle 45 may be employed to move the wheel 44 and particularly, its support pin 44a along the slot; it is thus possible to lock; and unlock the wheel 44 with respect to a bottom end abutment on the inside of the mount 43. A typical caster mounting is shown in U. S. Patent No. 1,895,150.

From the above description and the showing of the drawings, it will be apparent that our scaffold structure, unit or device It has a very high clearance factor, at the same time may be easily assembled and disassembled by one man, and is strong enough to support weights comparable to or greater than those of conventional structures. This is true, since the device is, in effect, divided into at least a pair of units, each of which has its own end section, floor part, and diagonal swing part. Common, inwardly-carried swing arm, member or shaft 18a serves as a pivot support for upper end portions of the diagonal swing parts 20 and 21 and 26 and 21' and is secured to the floor parts E and B. Each unit of the pair has swing arm, member or shaft 18 on which one end portion of an associated diagonal swing part is pivoted. The sections A and B, however, cooperatively fold to provide a collapsed structure whose parts are on substantially the same common plane. The floor or platform section has a pair of halves or parts C and C that fold directly on an associated side section A or B and indirectly, on an associated bridging section D or D.

It may be noted that the clamps 26 may be and are lifted out of position without any difiiculty by merely raising their associated side arm members 23. They are releasably locked in position by merely swinging them downwardly over and upon the transverse rail members 14d of the end secitons A and B.

As shown particularly in Figure 2 of the drawings, horizontally-opposed and spaced-apart upright end support or leg frames A and B have or define substantially planar outer sides, and the two parts C and C of the floor frame have or define a substantially planar horizontal upper side when the unit is in its erected position. Also, the pair of oblique or diagonal swing support or brace frames D and D are mounted at their lower ends intermediate vertical or length portions of the end frames A and B in an inwardly-offset relation with respect thereto by inwardly-projecting trunnion or mount parts 17, and at their upper ends, are connected together and to the transverse swing support shaft or member 18a in a downwardly or inwardly-offset relationship with respect to the floor parts C and C of the floor frame or section. The downwardly or inwardly offset relationship of the member 18a and its associated connections is provided at the ad iacent inner foldable ends of the floor frame by the downwardly-projecting Wings 31 and 31. It will be further noted that the floor frame has a horizontally-inward positioning as to the upright end or support columns 12 and 13 of the end frames A and B and thus, provides clearance for mounting a second and similar unit on the first unit.

What we claim is:

1. In a high clearance type of collapsible scaffold unit for vermal erection, a pair of upright horizontally-op posed and spaced-apart end support frames, said end support frames haying substantially planar vertical outer sides when the unitis erected, a fioor frame having a pair of floor parts, means at; the outer ends of said fioor parts securely and upwardly-detachablyconnecting them to upper ends of said end support frames, pivotmeans disposed beneath said floor frame and rotatably-pivotally connecting inner ends of said floor frame parts in an adjacent foldable relationship with each other, so that said floor frame parts may be released upwardly at their outer ends from said end frames and then swung downwardly to a collapsed position, a pair of oblique brace support frames operatively connected together at their upper ends and, sloping downwardly in an oblique relationship towards an adjacent, relation with said end frames, means connecting upper ends of said brace supp rt frames together and to said first-mentioned pivot means, pivot means rotatably-pivotally connecting intermediate length portions of said end frames to lower ends of adjacent brace support frames in an inwardly-extending relation with said end frames, so that said end frames may be swung downwardly along upper sides of said brace support frames when the unit is being collapsed.

2. A collapsible scaffold unit as defined in claim 1 wherein, said end frames each have a pair of upright end columns to interfit with corresponding end columns of a second and similar unit, and said floor frame has a horizontally-inward positioning with respect to said column members to provide clearance for mounting the second unit on the first-defined unit.

3. A collapsible scairold unit as defined in claim 1 wherein, a cross member is carried by the upper ends of each of said end frames, and said upwardly-detachable means has means to. securely clamp downwardly on said.

cross members when the unit is in an erected position.

4. A collapsible scaffold unit as defined in claim 1 wherein, each of said upwardly-detachable means has latching portions provided with yieldable latching fingers operatively associated therewith, and said end frames have top cross members, and said fingers are adapted to be moved downwardly into engagement over and about said top cross members.

5. In a, high clearance type of collapsible scaffold unit for vertical erection, a pair of upright horizontally-opposed and spaced-apart end support frames having substantially planar vertical outer sides therealong when the unit is erected, a pair of oblique brace support frames, means connecting upper ends of said brace support frames together, pivot means connecting intermediate length portions of said end frames adjacent their inner sides to lower end portions of said brace frames, so that said end frames may be, swung about said pivot means from a vertical erected, position downwardly upon upper sides of said brace support frames when the unit is being collapsed, a floor frame having a pair of floor parts with their inner ends in an adjacent foldable relation and defining a substantially planar upper'side when the unit is erected, downwardly-offset pivotal means rotatably-pivotally mounting the inner ends of said floor parts with respect to the upper ends of said brace support frames, so that said floor parts may be swung downwardly from their outer ends along an upper side of said brace support frames when the unit is being collapsed, and upwardlyreleasable detachable means securely connecting outer ends of said floor parts to upper ends of said end frames when the unit is erected.

6. In a high clearance type of collapsible scaffold unit for vertical erection and, that is suitable for tier build-up with a similar unit, a pair of upright horizontally-opposed and spaced-apart end support frames, said end support frames having substantially planar vertical outer sides when the unit is erected, a floor frame having a pair of floor parts with their inner ends in an adjacent foldable relation and defining a substantially planar upper side when the unit is erected, wings secured to 9 and projecting downwardly from the inner ends of said floor parts, a swing support member pivotally connecting said wings together, so that said floor parts may be swung downwardly about said member to collapse said floor frame, a pair of oblique brace frames connected at their upper ends to said swing support member, pivot means positioned in an inwardly-offset relation at an intermediate portion of the length of one end frame and rotatably-pivotally connected said one end frame to a lower end of one of said brace frames, so that said one end frame may swing about said pivot means to a position along an upper side of said one brace frame when the unit is being collapsed, a second pivot means positioned in an inwardly-offset relation at an intermediate portion of the length of the other of said end frames and rtatably-pivotally connecting said other end frame to a lower end of the other brace frame, so that said other end frame may swing about said pivot means to a position along an upper side of said one brace frame when the unit is being collapsed, and means upwardly-detachably and securely connecting an outer end of one floor part to said one end frame and upwardly-detachably and securely connecting the outer end of the other floor part to the upper end of said other end frame, so that said floor parts may be raised at their ends out of connection with said end frames and swung downwardly along said oblique brace frames when the unit is being collapsed.

7. A collapsible scaffold unit as defined in claim 6 wherein latch plug means is carried by one of said wings to latch-engage another of said wings and lock the parts of said floor structure in a bridging relation with said end frames when the unit is erected.

8. A construction as defined in claim 6 wherein, said wings have portions abutting each other when said floor frame defines a substantially planar upper side, and a spring-loaded snap latch plug is carried by one of said wings and engages within another of said wings to lock the parts of said fioor frame in the defined planar relationship when the unit is erected.

References Cited in the file of this patent UNITED STATES PATENTS 617,081 Conger Jan. 3, 1899 848,304 Hines Mar. 26, 1907 1,022,940 Hanson Apr. 9, 1912 1,141,385 Ellinger June 1, 1915 1,369,199 Snyder Feb. 22, 1921 2,593,386 Dirks Apr. 15, 1952 2,619,390 Johnson Nov. 25, 1952 2,640,734 Meng June 2, 1953 2,665,950 Johnson Jan. 12, 1954 2,708,607 Bingle' May 17, 1955 2,782,075 Pagan Feb. 19, 1957 FOREIGN PATENTS 590,281 Great Britain July 14, 1947 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,917 129 December l5 1959 Charles F. Grover et a1.

It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 39, for "Figure 11" read Figure 9 column 3, line 73, after "connector" for "T" read T's column 6, line 14, for "said" read side line 31, after "abutment" strike out the opening parenthesis; column 7, line 47, for "secitons" read sections Signed and sealed this 19th day of July 1960.

(SEAL) Attest:

KARL AXLINE ROBERT c. WATSON Attesting Ofiicer Commissioner of Patents 

